As a prior art of a lens system for applications such as in-vehicle application and monitoring application with a horizontal angle of view of about 90 degrees, a technology of a wide-angle lens disclosed in Patent Literature 1 is known. The wide-angle lens is configured of three groups that include a first lens including a glass lens, and second and third lenses each including an aspheric mold, and is usable for applications such as in-vehicle application and monitoring application.
As another example of such a wide-angle lens including three groups, a technology disclosed in Patent Literature 2 is known.